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Abstract:

A power converter includes a mounting substrate, a one-piece-type
connector including an input connector and an output connector, the input
connector and the output connector being formed in one-piece and arranged
side by side; and a case made of an electrically conductive material. The
one-piece-type connector includes lead terminals configured to connect
the input cable and the output cable to a power converting circuit and an
electrically conductive ground connection portion electrically connected
to the case through an electrically conductive member. The ground
connection portion includes a shield surface arranged to extend along at
least a portion of a side surface of the output connector.

Claims:

1. A power converter, comprising: a mounting substrate mounted with a
power converting circuit for converting electric power supplied from a
power supply and supplying the converted electric power to a load; a
one-piece-type connector including an input connector by which an input
cable for inputting the electric power supplied from the power supply to
the power converting circuit is connected to the mounting substrate and
an output connector by which an output cable for outputting the converted
electric power to the load is connected to the mounting substrate, the
input connector and the output connector being formed in one-piece and
arranged side by side; and a case made of an electrically conductive
material and configured to accommodate the mounting substrate and the
one-piece-type connector, wherein the one-piece-type connector includes
lead terminals configured to connect the input cable and the output cable
to the power converting circuit and an electrically conductive ground
connection portion electrically connected to the case through an
electrically conductive member, the ground connection portion including a
shield surface arranged to extend along at least a portion of a side
surface of the output connector.

2. The power converter of claim 1, wherein the one-piece-type connector
further includes a connecting portion to interconnect the input connector
and the output connector, the ground connection portion including a base
portion installed on the connecting portion and an upstanding portion
standing up from the base portion to extend along a side surface of the
output connector, the upstanding portion serving as the shield surface.

3. The power converter of claim 2, wherein the electrically conductive
member includes a screw extending through the base portion and the
mounting substrate to fix the ground connection portion to the case.

4. The power converter of claim 2, wherein the ground connection portion
further includes leg portions extending from the base portion so as to
make contact with the mounting substrate, each of the leg portions
including a bent portion flexed depending on a difference in an
attachment height of the lead terminals with respect to the mounting
substrate.

5. The power converter of claim 4, wherein the electrically conductive
member includes a grounding circuit formed on the mounting substrate, the
leg portions making contact with the grounding circuit.

6. The power converter of claim 2, wherein the mounting substrate has
through-holes formed at adjacent positions with a mounting position of
the connecting portion of the one-piece-type connector interposed
therebetween, the ground connection portion including leg portions
inserted into the through-holes and configured to fix the one-piece-type
connector at a predetermined height by being locked to the through-holes
in a state that the base portion is mounted to the connecting portion.

7. The power converter of claim 4, wherein the mounting substrate has
through-holes formed at adjacent positions with a mounting position of
the connecting portion of the one-piece-type connector interposed
therebetween, the leg portions being inserted into the through-holes and
being configured to fix the one-piece-type connector at a predetermined
height by being locked to the through-holes in a state that the base
portion is mounted to the connecting portion.

8. The power converter of claim 1, wherein each of the lead terminals
includes a crank-shaped bent portion flexed depending on a change in a
distance between the one-piece-type connector and the mounting substrate.

9. The power converter of claim 8, wherein the crank-shaped bent portion
of the lead terminal for the input connector and the crank-shaped bent
portion of the lead terminal for the output connector are oriented in
mutually different directions.

10. The power converter of claim 1, wherein each of the lead terminals
has a tip end bent to extend along a surface of the mounting substrate so
that the tip end is surface-mounted to the mounting substrate.

11. The power converter of claim 9, wherein the power converting circuit
includes an inverter circuit.

12. An illumination device, comprising: the power converter of claim 1; a
power supply configured to supply electric power to the power converter;
a lighting device as a load for receiving the electric power outputted
from the power converter and emitting light; an input cable extending
from the power supply, the input cable being connected to the input
connector of the one-piece-type connector of the power converter; and an
output cable extending to the lighting device, the output cable being
connected to the output connector.

13. The illumination device of claim 12, wherein the lighting device
includes an igniter connected to the power converter and an HID lamp
connected to the igniter.

Description:

FIELD OF THE INVENTION

[0001] The present invention relates to an illumination device that makes
use of a power supply device including a power converter and, more
particularly, to an EMS (Electromagnetic Susceptance) countermeasure
technology for increasing a noise resistance of the power converter.

BACKGROUND OF THE INVENTION

[0002] Along with the generalization of an HID (High Intensity Discharge)
lamp for motor vehicles, there is an increasing demand for the reduction
of a size and a weight of a head lamp unit for the HID lamp. This holds
true in case of an LED head lamp unit for motor vehicles.

[0003] The head lamp unit includes a head lamp portion and a power supply
device. The head lamp portion is a lighting device for emitting light.
The head lamp portion includes a socket to which a HID lamp is attached
and an ignitor connected to the socket. The power supply device includes
a battery power supply and a voltage converter for converting a voltage
of the electric power supplied from the battery power supply and
outputting the electric power to the ignitor. The voltage converter
includes an input connector to which an input cable for supplying the
electric power from the battery power supply is connected and an output
connector to which an output cable for outputting the electric power to
the ignitor is connected. In recent years, with a view to reduce the size
of a head lamp unit and to save costs, there is known a power converter
that makes use of a one-piece-type connector in which two input and
output connectors are one-piece formed with each other (see, e.g.,
Japanese Patent Application Publication No. 2003-132979). There is also
known a power converter in which a mounting substrate of a power
converter circuit having input and output connectors is fixed to an
accommodation case by screws (see, e.g., Japanese Patent No. 4479369)

[0004] The aforementioned power converter circuit is typically formed of
an inverter, a chopper circuit and so forth. It is known that, depending
on a loop antenna model or the like, the power converter circuit tends to
generate a radiation noise affecting an output voltage. In order to
reduce the size of the power converter, however, it is required to remove
an unnecessary noise or to suppress the influence of the radiation noise
at a significantly high level. In the event that an input connector and
an output connector are one-piece formed with each other, the electric
power inputted to the input connector is highly susceptible to a noise
contained in the electric power outputted from the output connector. This
is one of the causes hindering the size reduction of the power converter
employing a one-piece-type connector.

SUMMARY OF THE INVENTION

[0005] In view of the above, the present invention provides a power
converter capable of reducing the size of a one-piece-type connector and
capable of increasing an EMS resistance, and an illumination device using
the power converter.

[0006] In accordance with one aspect of the present invention, there is
provided a power converter, including: a mounting substrate mounted with
a power converting circuit for converting electric power supplied from a
power supply and supplying the converted electric power to a load; a
one-piece-type connector including an input connector by which an input
cable for inputting the electric power supplied from the power supply to
the power converting circuit is connected to the mounting substrate and
an output connector by which an output cable for outputting the converted
electric power to the load is connected to the mounting substrate, the
input connector and the output connector being formed in one-piece and
arranged side by side; and a case made of an electrically conductive
material and configured to accommodate the mounting substrate and the
one-piece-type connector, wherein the one-piece-type connector includes
lead terminals configured to connect the input cable and the output cable
to the power converting circuit and an electrically conductive ground
connection portion electrically connected to the case through an
electrically conductive member, the ground connection portion including a
shield surface arranged to extend along at least a portion of a side
surface of the output connector.

[0007] Preferably, the one-piece-type connector may further include a
connecting portion to interconnect the input connector and the output
connector, the ground connection portion including a base portion
installed on the connecting portion and an upstanding portion standing up
from the base portion to extend along a side surface of the output
connector, the upstanding portion serving as the shield surface.

[0008] Preferably, the electrically conductive member may include a screw
extending through the base portion and the mounting substrate to fix the
ground connection portion to the case.

[0009] Preferably, the ground connection portion further may include leg
portions extending from the base portion so as to make contact with the
mounting substrate, each of the leg portions including a bent portion
flexed depending on a difference in an attachment height of the lead
terminals with respect to the mounting substrate.

[0010] Preferably, the electrically conductive member may include a
grounding circuit formed on the mounting substrate, the leg portions
making contact with the grounding circuit.

[0011] Preferably, the mounting substrate may have through-holes formed at
adjacent positions with a mounting position of the connecting portion of
the one-piece-type connector interposed therebetween, the ground
connection portion including leg portions inserted into the through-holes
and configured to fix the one-piece-type connector at a predetermined
height by being locked to the through-holes in a state that the base
portion is mounted to the connecting portion.

[0012] Preferably, the mounting substrate may have through-holes formed at
adjacent positions with a mounting position of the connecting portion of
the one-piece-type connector interposed therebetween, the leg portions
being inserted into the through-holes and being configured to fix the
one-piece-type connector at a predetermined height by being locked to the
through-holes in a state that the base portion is mounted to the
connecting portion.

[0013] Preferably, each of the lead terminals may include a crank-shaped
bent portion flexed depending on a change in a distance between the
one-piece-type connector and the mounting substrate.

[0014] Preferably, the crank-shaped bent portion of the lead terminal for
the input connector and the crank-shaped bent portion of the lead
terminal for the output connector may be oriented in mutually different
directions.

[0015] Preferably, each of the lead terminals may have a tip end bent to
extend along a surface of the mounting substrate so that the tip end is
surface-mounted to the mounting substrate.

[0016] Preferably, the power converting circuit may include an inverter
circuit.

[0017] In accordance with another aspect of the present invention, there
is provided an illumination device, including: the power converter of
above disclosed one aspect of the present invention; a power supply
configured to supply electric power to the power converter; a lighting
device as a load for receiving the electric power outputted from the
power converter and emitting light; an input cable extending from the
power supply, the input cable being connected to the input connector of
the one-piece-type connector of the power converter; and an output cable
extending to the lighting device, the output cable being connected to the
output connector.

[0018] Preferably, the lighting device may include an igniter connected to
the power converter and an HID lamp connected to the igniter.

[0019] With the present embodiment, the one-piece-type connector of the
power converter includes a ground connection portion having a shield
surface on at least a portion of the side surface near the output
connector. The ground connection portion guides an unnecessary radiation
noise, which would otherwise be inputted from the output connector to the
input connector, toward the case. It is therefore possible to increase
the EMS resistance of the power converter and to reduce the size of the
one-piece-type connector.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIG. 1 is a section view showing the configuration of an HID head
lamp unit that makes use of a power supply device including a power
converter according to one embodiment of the present invention.

[0021] FIG. 2 is a circuit diagram of the HID head lamp unit.

[0022] FIG. 3A is a perspective view showing the overall configuration of
the power converter according to one embodiment of the present invention
and FIG. 3B is an exploded perspective view showing a mounting substrate
and a case of the power converter.

[0023] FIG. 4A is a perspective view of a ground connection portion for
use in a one-piece-type connector attached to the power converter, FIG.
4B is a perspective view for explaining how to install the ground
connection portion to a one-piece-type connector and FIG. 4c is a
perspective view of the one-piece-type connector completed.

[0024]FIG. 5A is a perspective view showing a lead terminal provided in
the bottom of the one-piece-type connector and

[0025]FIG. 5B is a side view showing the lead terminal soldered to the
mounting substrate.

[0026]FIG. 6 is a perspective view illustrating how to connect a shielded
output cable to the one-piece-type connector.

[0027] FIG. 7 is a section view of the one-piece-type connector and the
shielded output cable.

[0028]FIG. 8A is a perspective view of a ground connection portion having
leg portions locked to a mounting substrate in a first modified example
of the aforementioned embodiment,

[0029]FIG. 8B is a perspective view showing the ground connection portion
attached to the one-piece-type connector body and

[0030]FIG. 8C is a section view of the ground connection portion gripping
and holding the mounting substrate.

[0031]FIG. 9A is a perspective view- of a one-piece-type connector having
a surface-mounting lead terminal in a second modified example of the
aforementioned embodiment, with the lead terminal illustrated on an
enlarged scale, and

[0032]FIG. 9B is a perspective view of the one-piece-type connector
surface-mounted to the mounting substrate.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033]FIG. 1 is a section view showing an HID head lamp unit 1 that makes
use of a power converter 6 in accordance with one embodiment of the
present invention. FIG. 2 is a schematic circuit diagram of the HID head
lamp unit 1. The HID head lamp unit 1 includes a power supply device 2
and a head lamp portion 3. The power supply device 2 includes a
vehicle-mounted battery 4 having an output power of 12 V and a power
converter 6 to which DC power is inputted from the battery 4 through a
switch SW and an input cable 5. The power converter 6 includes a DC/AC
converting circuit 16 including an inverter circuit as a power converting
circuit. The power converter 6 converts a DC voltage of 12 V to a
high-frequency AC voltage having a frequency of 20 kHz to 100 kHz and
outputs the AC voltage thus converted.

[0034] The head lamp portion 3 is a lighting device for emitting light.
The head lamp portion 3 includes a HID lamp 7, a socket 8, an ignitor 9
supplying electric power to the socket 8, an output cable 10, a
reflecting plate 11, a lamp case 12 accommodating the components
mentioned just above, and a light lens 13. The HID lamp 7 is mounted to
the socket 8. The output cable 10 interconnects the power converter 6 and
the ignitor 9. The power converter 6 includes a one-piece-type connector
17 in which an input connector 18 connected to the input cable 5 and an
output connector 19 connected to the output cable 10 are arranged in
adjacent positions and are one-piece formed with each other. The ignitor
9 increases the output voltage of the power converter 6 to about 25 kV
and outputs the voltage thus increased. In the head lamp unit 1, other
configurations than the power converter 6 is well-known in the art and
will not be described in detail herein.

[0035] FIG. 3A is a perspective view of the power converter 6 and FIG. 3B
is an exploded perspective view of the power converter 6. The power
converter 6 includes a mounting substrate 14 having an electric
insulation property, an aluminum-die-cast case 15 as an electrically
conductive member for accommodating the mounting substrate 14, and a case
cover 30 for covering the case 15. The case 15 has screw holes 15a, 15b
and 15c used in attaching the power converter 6 to an attachment frame of
a motor vehicle or the like not shown in the drawings. The case 15 serves
as a grounding mechanism with respect to the mounting substrate 14.

[0036] The DC/AC converting circuit 16 and the one-piece-type connector
17, to which the input and output cables (the cables 5 and 10 shown in
FIG. 2) are connected, are mounted to the mounting substrate 14. The
one-piece-type connector 17 includes an input connector 18 to which the
input cable 5 shown in FIG. 2 is connected, an output connector 19 to
which the output cable 10 is connected, a connecting portion 20 for
interconnecting the two connectors 18 and 19, and a ground connection
portion 21. The ground connection portion 21, the connecting portion 20,
and the mounting substrate 14 have through-holes 21b, 20a and 14a into
which screws 22 are inserted. In the following description, for the sake
of convenience in description, the structure formed of the input
connector 18, the output connector 19, and the connecting portion 20 will
be referred to as a body of the one-piece-type connector 17.

[0037] The ground connection portion 21 provided above the connecting
portion 20 has a shield surface 21a standing up along a portion of the
side surface of the output connector (see FIG. 4A to be described later).
The ground connection portion 21 is fixed to the one-piece-type connector
17 by inserting a set screw 22 as an electrically conductive member into
the through-hole 21b of the ground connection portion 21, the
through-hole 20a of the connecting portion 20, and a through-hole 14a of
the mounting substrate 14 and then tightening the set screw 22 to a
thread hole 15d of the case 15. Since the ground connection portion 21 is
connected to the electrically conductive case 15 by the set screw 22, the
unnecessary radiation noise outputted from the output connector 19 is
guided toward the case 15 by the ground connection portion 21. This
reduces the influence of the unnecessary radiation noise on the input
connector 18. Accordingly, it is possible to shorten the distance between
the input connector 18 and the output connector 19. As a result, it
becomes possible to reduce the size of the power converter 6 employing
the one-piece-type connector 17.

[0038] Due to the vibration transmitted from a motor vehicle to which the
head lamp unit 1 is attached, the one-piece-type connector 17 may be
applied with a pulling force through the cables 5 and 10 connected to the
input connector 18 and the output connector 19.

[0039] Since the one-piece-type connector 17 is screw-fixed to the case
15, the one-piece-type connector 17 has an increased resistance against
the pulling force. Since the ground connection portion 21 is directly
connected to the case 15, there is provided an advantage that an
unnecessary antenna loop as a cause of generating a noise is not formed
in the mounting substrate 14.

[0040] Description will now be made on a manufacturing method of the power
converter 6. First, the lead terminals (see FIG. 5) of the body of the
one-piece-type connector 17 are mounted into the through-holes of the
mounting substrate 14. Then, the ground connection portion 21, the body
of the one-piece-type connector 17 and the mounting substrate 14 are
fixed to the case 15 by the screw 22. Thereafter, the mounting substrate
14 is potted (heaped) with a filler material. After the filler material
is cured, the case cover 30 is attached to the case 15 by inserting the
screw 31 through the case cover 30 and tightening the screw 31 to the
thread hole 32. The power converter 6 is manufactured in the
aforementioned order.

[0041] FIG. 4A is a perspective view showing the configuration of the
ground connection portion 21. FIG. 4B is a perspective view for
explaining how to attach the ground connection portion 21 to the body of
the one-piece-type connector 17. FIG. 4c is a perspective view of the
one-piece-type connector 17 mounted to the mounting substrate 14. The
ground connection portion 21 includes a base portion 21c installed on the
connecting portion 20, an upstanding portion having a shield surface 21a
standing up from the base portion 21c along the side surface of the
connecting portion 20 of the output connector 19, and plate-like leg
portions 21d and 21e. The shield surface 21a is arranged on at least a
portion of the side surface of the output connector 19. For example, the
shield surface 21a may stand up so as to extend along the surface of the
leg portion 21d or 21e. Since the shield surface 21a is arranged to exist
between the input connector 18 and the output connector 19 as shown in
the drawings, it is possible to effectively reduce the influence of a
noise on the input connector 18. The mounting substrate 14 includes a
rectangular grounding wiring line 14b (hatched in FIG. 4c) through which
the through-hole 14a extends. The grounding wiring line 14b is an
electrically conductive member differing from the screw 22. The leg
portions 21d and 21e extend from the base portion 21c toward the mounting
substrate 14 and have a length large enough to make contact with the
grounding wiring line 14b. The one-piece-type connector 17 has
slit-shaped grooves 17a and 17b (see FIG. 5A) to which the leg portions
21d and 21e are fitted when the base portion 21c of the ground connection
portion 21 is placed on the connecting portion 20. The leg portions 21d
and 21e have lug portions 21f and 21g formed at the opposite sides
thereof. The lug portions 21f and 21g are locked inside the grooves 17a
and 17b to fix the ground connection portion 21 to the one-piece-type
connector 17.

[0042] The ground connection portion 21 is connected to the case 15
through the screw 22. Since the leg portions 21d and 21e make contact
with the grounding wiring line 14b, the noise grounding route is
increased and the electric resistance is reduced. This makes it possible
to stably reduce the noise. The grounding wiring line 14b is preferably
formed into a linear shape including the through-hole 14a as shown in
FIG. 4c, so as not to form an antenna loop as a cause of generating an
unnecessary noise.

[0043] The one-piece-type connector 17 includes lead terminals 23a through
23g arranged on the lower surface thereof (see FIG. 5A). The lead
terminals 23a through 23g extend so that one ends thereof can be
electrically connected to the connectors of the input cable 5 and the
output cable 10 and the other ends thereof can be inserted into the
through-holes formed in the mounting substrate 14. The other ends of the
lead terminals 23a through 23g are mounted (soldered) to the mounting
substrate 14 through through-holes formed in the mounting substrate 14.
Then, the ground connection portion 21 is attached to the connecting
portion 20 by the screw 22. The leg portions 21d and 21e include bent
portions 21h and 21i formed at the tip ends thereof so that the bent
portions 21h and 21i can be flexed when the ground connection portion 21
is pressed downward. The bent portions 21h and 21i are flexed depending
on the difference in the installation height of the lead terminals 23a
through 23g attributable to the manufacturing error or the use
environment. Thus the bent portions 21h and 21i keep the lead terminals
23a through 23g in good contact with the grounding wiring line 14b. While
the bent portions 21h and 21i are connected to the grounding wiring line
14b by pressure contact, it may be possible to solder the bent portions
21h and 21i to the grounding wiring line 14b after the ground connection
portion 21 is installed in place.

[0044]FIG. 5A is a perspective view showing the lead terminals 23a
through 23g of the one-piece-type connector 17. FIG. 5B is a side view
showing the one-piece-type connector attached to the mounting substrate
14. Since the respective lead terminals 23a through 23g are identical in
shape, only the lead terminal 23a will be described herein below. As
shown in FIGS. 5A and 5B, the lead terminal 23a includes a crank-shaped
bent portion 23h extending parallel to the mounting substrate 14. When
the ground connection portion 21 is attached to the connecting portion 20
by the screw 22, the leg portions 21d and 21e of the ground connection
portion 21 exert forces by which the body of the one-piece-type connector
17 is urged to move away from the mounting substrate 14. However, the
crank-shaped bent portion 23h is flexed to absorb the forces, thereby
preventing the lead terminal 23a from being separated from a solder.
Similarly, the crank-shaped bent portion 23h can prevent the lead
terminal 23a from being separated from a solder, in the event that the
distance between the body of the one-piece-type connector 17 and the
mounting substrate is changed depending on the use environment after the
bent portions 21h and 21i are soldered to the grounding wiring line 14b.
The distance change caused by the use environment is generated by, e.g.,
the temperature change or the vibration transmitted from a motor vehicle
to which the case 15 is attached. While the opposite ends of the
crank-shaped bent portion 23h are bent at 90 degrees, they may be bent at
an obtuse angle as long as the function of the crank-shaped bent portion
23h flexed depending on the change in the distance between the connector
17 and the mounting substrate 14 is not impaired. The crank-shaped bent
portions of the lead terminals 23a through 23d of the input connector 18
and the crank-shaped bent portions of the lead terminals 23e through 23g
of the output connector 19 may be oriented in the same direction or may
be oriented in different directions, e.g., in 90-degree different
directions as shown in FIG. 5A. This makes it possible to reduce the
change in the posture of the one-piece-type connector 17 caused by the
lead terminal 23a being flexed.

[0045]FIG. 6 is a perspective view illustrating how to connect the output
cable 10 to the output connector 19 of the one-piece-type connector 17.
The output cable 10 includes a shield member 24 arranged at the tip end
thereof to completely cover the output connector 19. FIG. 7 is a section
view of the output cable 10 taken along line VII-VII in FIG. 6.

[0046] The shield member 24 of the output cable 10 includes a connection
member 24a protruding inward. Upon inserting a connector 25 of the tip
end of the output cable 10 into the output connector 19 of the
one-piece-type connector 17, the connection member 24a is connected to
the shield surface 21a of the ground connection portion 21. If the shield
surface 21a of the ground connection portion 21 is formed on only the
side surface of the output connector 19 facing the connecting portion 20,
the output cable 10 having the shield member 24 reduces the influence of
a noise on the signal flowing not only through the input connector 18 but
also through the wiring line of the mounting substrate 14. If the shield
surface of the ground connection portion 21 is formed to surround the
side surface of the output connector 19, the same noise reduction effect
can be obtained even when an output cable not provided with the shield
member 24 is used in place of the output cable 10. For the sake of
understanding of the invention, FIG. 7 shows a state that the ground
connection portion 21 and the grounding wiring line 14b of the mounting
substrate 14 are electrically connected to the thread hole 15d of the
case 15 by the screw 22.

[0047] As described above, the power converter 6 is configured to increase
the EMS resistance of the one-piece-type connector 17 using the ground
connection portion 21 and to reduce the size of the one-piece-type
connector 17. It is also possible to reduce the overall size of the head
lamp unit 1 as an illumination device employing the power converter 6.
Since the one-piece-type connector 17 and the ground connection portion
21 are directly attached to the case 15 by use of the screw 22, the
length of the grounding wiring line is reduced and the generation of the
unnecessary noise is prevented. Since the one-piece-type connector is
directly connected to the case, the one-piece-type connector has an
increased resistance against the pulling force of the cables connected to
the input connector 18 and the output connector 19. Since one or both of
the ground connection portion 21 and the lead terminals 23a through 23g
is provided with the bent portions, the solder portions of the ground
connection portion 21 and the lead terminals 23a through 23g are applied
with low stresses and are prevented from being separated from the
mounting substrate 14.

[0048] Preferably, the one-piece-type connector 17 and the ground
connection portion 21 are directly attached to the case 15 by use of the
screw 22. Considering the circuit design of the mounting substrate 14, it
may be possible to employ a configuration in which the one-piece-type
connector 17 and the ground connection portion 21 are attached to the
mounting substrate 14 by the screw 22 and then connected to the case 15
by way of one or both of the screw 22 and the leg portions 21d and 21e.
In this case, it is possible to obtain the noise reduction effect
provided by the ground connection portion 21. Since one or both of the
ground connection portion 21 and the lead terminal 17b of the
one-piece-type connector 17 is provided with the bent portions, the
solder portions of the ground connection portion 21 and the lead
terminals 23a through 23g are applied with low stresses and are prevented
from being separated from the mounting substrate 14.

FIRST MODIFIED EXAMPLE

[0049]FIG. 8A is a perspective view showing a ground connection portion
26 in accordance with a first modified example. FIG. 8B is a perspective
view of the one-piece-type connector 17 to which the ground connection
portion 26 is mounted. The ground connection portion 26 includes a pair
of leg portions 26a and 26b differing in shape from the ground connection
portion 21 described above. FIG. 8C is a section view showing the leg
portions 26a and 26b attached to the mounting substrate 14. The mounting
substrate 14 includes a pair of through-holes 14c and 14d formed at
adjacent positions with the mounting position of the connecting portion
20 interposed therebetween. The tip ends of the leg portions 26a and 26b
come close toward each other so that the leg portions 26a and 26b, when
inserted into the through-holes 14c and 14d, grip the mounting substrate
14 and fix the body of the one-piece-type connector 17 at a predetermined
height. For the removal-preventing purpose, the leg portions 26a and 26b
are provided at the tip ends with locking portions 26c and 26d bent such
that locking portions 26c and 26d extend toward each other and then
extend away from each other. The ground connection portion 26 is formed
of an electrically conductive spring member having a thickness of, e.g.,
0.4 mm or less. Since the one-piece-type connector 17 mounted with the
ground connection portion 26 is fixed to the mounting substrate 14 at the
predetermined height, it is possible to prevent the body of the
one-piece-type connector 17 from floating when the lead terminals 23a
through 23g are soldered. In other words, the locking portions 26c and
26d have an advantage in that there is no need to use a jig for
tentatively pressing the body of the one-piece-type connector 17 and
preventing the floating of the body of the one-piece-type connector 17.

[0050] If the grounding wiring line 14b is not formed on the mounting
substrate 14 and if the ground connection portion 26 is not soldered to
the mounting substrate 14, the locking portions 26c and 26d are arranged
in such positions where the locking portions 26c and 26d can move up and
down by a little distance (e.g., 0.1 mm) in a state that the ground
connection portion 26 grips the mounting substrate 14. The portions
movable in the up-down direction have an advantage in that they can
absorb the stresses attributable to the change in the distance between
the one-piece-type connector 17 and the mounting substrate 14 when the
one-piece-type connector 17 and the mounting substrate 14 are fixed to
the case 15 by the screw 22 and when the illumination device is normally
used. Even if the grounding wiring line 14b is formed on the mounting
substrate 14, there is provided an advantage in that, after the
one-piece-type connector 17 is attached to the case 15, the ground
connection portion 26 can be soldered to the mounting substrate 14 in
such a position where the ground connection portion 26 does not apply any
load on the soldered portions of the lead terminals 23a through 23g.

[0051] The locking portions 26c and 26d may have other well-known shapes
as long as the aforementioned advantages can be provided by fixing the
body of the one-piece-type connector at the predetermined height while
assuring the easy insertion of the locking portions 26c and 26d into the
through-holes 14c and 14d. Instead of gripping the mounting substrate 14,
the locking portions 26c and 26d may have, e.g., a snap-fit shape so that
the locking portions 26c and 26d can pass through the through-holes 14c
and 14d and can interpose the front and rear surfaces of the mounting
substrate 14 therebetween.

[0052] A curved portion having a U-like cross-sectional shape or a
crank-shaped bent portion having the same shape as the crank-shaped bent
portion 23h of the lead terminal 23a may be formed in the region of each
of the leg portions 26a and 26b nearer to the base end than the locking
portions 26c and 26d. In this case, it is possible to further enhance the
ability to absorb the stresses attributable to the change in the distance
between the one-piece-type connector 17 and the mounting substrate 14.

SECOND MODIFIED EXAMPLE

[0053]FIG. 9A is a perspective view of a one-piece-type connector 27 in
accordance with a second modified example, which has lead terminals 27a
through 27g not through-hole-mounted but surface-mounted to the mounting
substrate 14. In FIG. 9A, the lead terminal 27a is shown on an enlarged
scale. FIG. 9B is a perspective view of the one-piece-type connector 27
surface-mounted to the double-side mounting substrate 28. Other
configurations of the one-piece-type connector 27 than the lead
terminals, including the ground connection portion 21 or 26, remain the
same as the configurations of the one-piece-type connector 17. The lead
terminals 27a through 27g are identical in configuration. Description
will now be made on the lead terminal 27a. The lead terminal 27a includes
not only a crank-shaped bent portion 27h flexed to absorb the change in
the distance between the lead terminal 27a and the double-side mounting
substrate 28 but also a surface-mounted bent portion 27i which is bent to
extend along the surface of the substrate 28. With this configuration,
the one-piece-type connector 27 is surface-mounted to the substrate 28.

[0054] The configurations of the power converter in accordance with the
present invention are not limited to the configurations of the embodiment
and the modified examples described above but may be modified in many
different forms without departing from the scope and spirit of the
invention. For example, contact points connected to the grounding wiring
line may be formed inside the through-holes 14c and 14d of the mounting
substrate 14. The locking portions of the ground connection portion 26
may not be soldered to the substrate. In this case, the locking portions
26c and 26d are movable in the up-down direction. This provides an
advantage in that it is possible to reduce the stresses applied to the
lead terminals of the one-piece-type connector 17 and to increase the
grounding route.

[0055] The power converter in accordance with the present invention can
find its application not only in a motor vehicle but also in a variety of
illumination devices that require an increased resistance against the
noise generated in a power converting circuit.

[0056] While the invention has been shown and described with respect to
the embodiments, the present invention is not limited thereto. It will be
understood by those skilled in the art that various changes and
modifications may be made without departing from the scope of the
invention as defined in the following claims.

Patent applications by PANASONIC CORPORATION

Patent applications in class CURRENT AND/OR VOLTAGE REGULATION

Patent applications in all subclasses CURRENT AND/OR VOLTAGE REGULATION